Deep hybrid power battery system and new energy automobile

Abstract

The invention relates to the field of batteries, and discloses a deep hybrid power battery system and a new energy automobile. The battery system comprises a DC / DC module, a hybrid battery module, a bidirectional Buck-boost circuit structure and a capacitor module, the four parts are correspondingly connected through circuits, the hybrid battery module is formed by connecting a plurality of groups of hybrid batteries in parallel, and each hybrid battery is formed by connecting a lead-acid battery monomer and a plurality of lithium battery monomers in series. According to the battery system, the hybrid battery modules which are connected in series and in parallel are adopted, the battery system is formed by connecting a lead-acid battery monomer and a plurality of lithium battery monomers in series, the SOC of the lead-acid battery is linearly changed with the terminal voltage within a certain interval, and accurate calculation and calibration of the SOC of the hybrid battery modules can be realized; and a capacitor module and a bidirectional Buck-boost circuit structure are arranged, so that reliable power output of the battery system at low temperature is ensured, power supplementation is performed, and the problem of poor performance is solved fundamentally.

Description

Technical Field

[0001] The present invention relates to the field of batteries, and in particular to a deep hybrid power battery system and a new energy vehicle. Background Art

[0002] With the rapid development of new energy vehicles, the requirements for the use of batteries are getting higher and higher. The low-temperature performance of commonly used lithium batteries is poor, and the battery management system is relatively complex. Since the terminal voltage changes relatively slowly within the available state of charge (SOC) range, a more complex SOC estimation algorithm needs to be adopted, which occupies a large amount of controller data processing space, increasing the cost and development difficulty of the battery management system. Under low temperature conditions, lithium batteries power the heating system of the thermal management system, which will produce large energy losses and reduce the efficiency of the power battery system. The hybrid battery packs that have appeared so far are just independent groups of lithium batteries and other batteries, and the batteries that are used for power supply are selected in specific occasions. This hybrid battery pack cannot fundamentally solve the problems of poor low-temperature performance, difficult SOC estimation, and poor estimation accuracy. Summary of the invention

[0003] In order to overcome the above technical problems, the present invention provides a hybrid battery power battery system, which adopts a hybrid battery module connected in series and parallel. By adopting a lead-acid battery cell and a plurality of lithium battery cells in series, the SOC of the lead-acid battery changes linearly with the terminal voltage within a certain range, and the SOC of the hybrid battery module can be accurately calculated and calibrated; a capacitor module and a bidirectional Buck-boost circuit structure are provided to ensure that the battery system still has reliable power output at low temperatures, thereby solving the problem of poor low-temperature performance from the root.

[0004] In order to achieve the above object, the present invention provides a deep hybrid battery system on one hand, the battery system comprising:

[0005] A DC / DC module, wherein a positive input terminal of the DC / DC module is connected to a positive terminal of an external DC bus, and a negative input terminal of the DC / DC module is connected to a negative terminal of the external DC bus;

[0006] A hybrid battery module, wherein the positive terminal of the hybrid battery module is connected to the positive output terminal of the DC / DC module, the negative terminal of the hybrid battery module is connected to the negative output terminal of the DC / DC module, and the hybrid battery module is composed of multiple groups of hybrid batteries connected in parallel, and the hybrid battery is composed of a lead-acid battery cell and multiple lithium battery cells connected in series;

[0007] A bidirectional Buck-boost circuit structure, wherein one end of a positive electrode circuit of the bidirectional Buck-boost circuit structure is connected to a positive terminal of the hybrid battery module, and one end of a negative electrode circuit of the bidirectional Buck-boost circuit structure is connected to a negative terminal of the hybrid battery module;

[0008] A capacitor module, wherein the positive terminal of the capacitor module is connected to the other end of the positive line of the bidirectional Buck-boost circuit structure, the negative terminal of the capacitor module is connected to the other end of the negative line of the bidirectional Buck-boost circuit structure, and the positive terminal of the capacitor module is connected to the positive output terminal of the DC / DC module, and the negative terminal of the capacitor module is connected to the negative output terminal of the DC / DC module.

[0009] Preferably, the lead-acid battery cells and the lithium battery cells have the same battery capacity.

[0010] Preferably, the battery system further comprises a control detector, wherein the control detector is used for:

[0011] Obtaining the charge and discharge currents of the lead-acid battery cells and the lithium battery cells, and calculating the charge state of the single cells of the hybrid battery according to the charge and discharge currents of the lead-acid battery cells and the lithium battery cells and formula (1),

[0012]

[0013] Among them, SOC is the state of charge of the lead-acid battery cell and the lithium battery cell, SOC0 is the initial state of charge of the lead-acid battery cell and the lithium battery cell, i is the charge and discharge current of the lead-acid battery cell and the lithium battery cell, and C is the battery capacity of the lead-acid battery cell and the lithium battery cell.

[0014] Preferably, the control detector is used to:

[0015] Obtaining the terminal voltage of the lead-acid battery cell;

[0016] Calculating the state of charge of the lead-acid battery cell according to the terminal voltage of the lead-acid battery cell and formula (2), and calibrating the state of charge of the hybrid battery,

[0017]

[0018] Among them, SOC x is the state of charge of the lead-acid battery cell, u x is the terminal voltage of the lead-acid battery cell, u H is the highest terminal voltage of the lead-acid battery cell, u L is the lowest terminal voltage of the lead-acid battery cell, SOC HSOC is the state of charge corresponding to the highest terminal voltage of the lead-acid battery cell. L The state of charge corresponding to the lowest terminal voltage of the lead-acid battery cell;

[0019] According to the state of charge of the lead-acid battery cells connected in series being the same as the state of charge of the lithium battery cells, the state of charge of the hybrid battery is calibrated.

[0020] Preferably, the capacitor module is composed of multiple groups of super capacitors connected in parallel, and the super capacitor group is composed of multiple super capacitors connected in series.

[0021] Preferably, the control detector is used to:

[0022] Obtain the SOC of the lithium battery cell, and obtain the maximum discharge current of the lithium battery cell according to formula (3).

[0023]

[0024] Among them, i max is the maximum discharge current of the lithium battery cell, C is the battery capacity of the lead-acid battery cell and the lithium battery cell, SOC is the current state of charge of the lithium battery cell, SOC L is the state of charge corresponding to the lowest terminal voltage of the lead-acid battery cell, and Δt is the discharge time.

[0025] Preferably, the control detector is used to:

[0026] The rated discharge power of the battery system is set, the total voltage of the hybrid battery module and the total voltage of the capacitor module are obtained, and the discharge power composition of the battery system is determined according to formula (4).

[0027] P=i max U1+i c U2, (4)

[0028] Wherein, P is the discharge power set by the battery system, U1 is the total voltage of the hybrid battery module, U2 is the total voltage of the capacitor module, i max is the maximum discharge current of the lithium battery cell;

[0029] When the discharge power of the hybrid battery module meets the rated discharge power of the battery system, c The discharge current is 0;

[0030] When the discharge power of the hybrid battery module does not meet the rated discharge power of the battery system, the discharge current of the capacitor module is determined according to formula (5):

[0031]

[0032] Wherein, P is the discharge power set by the battery system, U1 is the total voltage of the hybrid battery module, U2 is the total voltage of the capacitor module, i max is the maximum discharge current of the lithium battery cell.

[0033] Preferably, the bidirectional Buck-boost circuit structure includes:

[0034] A first diode, wherein an anode of the first diode is connected to one end of a positive electrode line of the bidirectional Buck-boost circuit structure;

[0035] a first switch, wherein one end of the first switch is connected to the anode of the first diode, and the other end of the first switch is connected to the cathode of the first diode;

[0036] a second switch, wherein one end of the second switch is connected to the cathode of the first diode, and the other end of the second switch is connected to one end of the cathode line of the bidirectional Buck-boost circuit structure;

[0037] a second diode, wherein an anode of the second diode is connected to one end of the second switch, a cathode of the second diode is connected to the other end of the second switch, and a cathode of the second diode is connected to the other end of the negative electrode line of the bidirectional Buck-boost circuit structure;

[0038] A first inductor, one end of the first inductor is connected to the anode of the second diode, and the other end of the first inductor is connected to the other end of the anode line of the bidirectional Buck-boost circuit structure.

[0039] A second aspect of the present invention provides a new energy vehicle, comprising a deep hybrid battery system as described in any one of the above claims.

[0040] Through the above technical solution, the battery system adopts a hybrid battery module connected in series and parallel, which is composed of a lead-acid battery cell and multiple lithium battery cells in series, and the capacity of the lead-acid battery cell and the lithium battery cell are set to be the same, ensuring that the SOC calculation formula can realize the calculation of the SOC of the single battery in the entire hybrid battery group to obtain the SOC in the hybrid battery group. At the same time, the SOC of the lead-acid battery changes linearly with the terminal voltage within a certain range, which can realize the accurate calculation and calibration of the SOC of the hybrid battery module; a series-parallel capacitor module and a bidirectional Buck-boost circuit structure are set, the hybrid battery module preferentially charges the capacitor module, and the hybrid battery module and the capacitor module are deeply mixed to ensure that the battery system still has reliable power output at low temperatures, thereby solving the problem of poor low-temperature performance from the root. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a structural connection block diagram of a deep hybrid battery system according to an embodiment of the present invention;

[0042] Figure 2 Schematic diagram of circuit connection of a deep hybrid battery system according to one embodiment of the present invention.

[0043] Description of Reference Numerals

[0044] 1. DC / DC module 2. Hybrid battery module

[0045] 3. Capacitor module 4. Bidirectional Buck-boost circuit structure

[0046] 21. Hybrid battery 31. Supercapacitor group

[0047] 41. First diode 42. Second diode

[0048] 43. First switch 44. Second switch

[0049] 45. first inductor 211, lithium battery cell

[0050] 212, lead-acid battery monomer 311, supercapacitor DETAILED DESCRIPTION

[0051] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0052] In the embodiments of the present invention, unless otherwise specified, directional words such as "up, down, top, bottom" are usually used with reference to the directions shown in the drawings or are used to describe the relative positional relationships of components in the vertical, perpendicular or gravity direction.

[0053] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0054] like Figure 1FIG. 1 is a structural connection block diagram of a deep hybrid battery system according to an embodiment of the present invention; Figure 1 In the embodiment, the battery system includes a DC / DC module 1, a hybrid battery module 2, a bidirectional Buck-boost circuit structure 4 and a capacitor module 3; specifically, the positive input terminal of the DC / DC module 1 is connected to the positive terminal of the external DC bus, and the negative input terminal of the DC / DC module 1 is connected to the negative terminal of the external DC bus; the positive terminal of the hybrid battery module 2 is connected to the positive output terminal of the DC / DC module 1, and the negative terminal of the hybrid battery module 2 is connected to the negative output terminal of the DC / DC module 1, and the hybrid battery module 2 is composed of a plurality of hybrid batteries 21 connected in parallel, and the hybrid battery 21 is composed of a lead-acid battery cell 212 and a plurality of lithium battery cells 2 11 are connected in series; one end of the positive line of the bidirectional Buck-boost circuit structure 4 is connected to the positive end of the hybrid battery module 2, and one end of the negative line of the bidirectional Buck-boost circuit structure 4 is connected to the negative end of the hybrid battery module 2; the positive end of the capacitor module 3 is connected to the other end of the positive line of the bidirectional Buck-boost circuit structure 4, the negative end of the capacitor module 3 is connected to the other end of the negative line of the bidirectional Buck-boost circuit structure 4, and the positive end of the capacitor module 3 is connected to the positive output end of the DC / DC module 1, and the negative end of the capacitor module 3 is connected to the negative output end of the DC / DC module 1.

[0055] Through the above technical solution, the battery system adopts a hybrid battery module connected in series and parallel. By adopting a lead-acid battery cell and multiple lithium battery cells in series, the SOC of the lead-acid battery changes linearly with the terminal voltage within a certain range, which can realize accurate calculation and calibration of the SOC of the hybrid battery module; setting a capacitor module and a bidirectional Buck-boost circuit structure ensures that the battery system still has reliable power output at low temperatures, thereby solving the problem of poor low-temperature performance from the root.

[0056] Considering the convenience of calculating the SOC of the hybrid battery module 2 in the deep hybrid battery system; in one embodiment of the present invention, the battery capacity of the lead-acid battery cell 212 and the lithium battery cell 211 are the same. In order to accurately calculate the SOC of the single battery in the hybrid battery module 2, in one embodiment of the present invention, the battery system also includes a control detector (not shown in the figure), which first obtains the charge and discharge current of the lead-acid battery cell 212 and the lithium battery cell 211, and calculates the charge state of the single battery of the hybrid battery 21 according to formula (1).

[0057] Among them, SOC is the state of charge of the lead-acid battery cell 212 and the lithium battery cell 211, SOC0 is the initial state of charge of the lead-acid battery cell 212 and the lithium battery cell 211, i is the charge and discharge current of the lead-acid battery cell 212 and the lithium battery cell 211, and C is the battery capacity of the lead-acid battery cell 212 and the lithium battery cell 211. Since SOC0 and i are the same for the single batteries in the series battery group, as long as C is the same, the SOC of the lead-acid battery cell 212, the lithium battery cell 211, and the batteries of the entire series group are the same, so that the accurate SOC of the hybrid battery 21 is obtained according to the SOC of the lead-acid battery cell 212 and the lithium battery cell 211 in the series hybrid battery.

[0058] In order to realize SOC calibration of the hybrid battery 21, in one embodiment of the present invention, the SOC calibration of the hybrid battery 21 can be realized based on the linear variation relationship between the SOC of the lead-acid battery cell 211 and the terminal voltage within a certain range; the control detector first obtains the terminal voltage of the lead-acid battery cell 212; and calculates the charge state of the lead-acid battery cell 212 according to the terminal voltage of the lead-acid battery cell 212 and formula (2), and calibrates the charge state of the hybrid battery 21.

[0059] Among them, SOC x is the state of charge of the lead-acid battery cell 212, u x is the terminal voltage of the lead-acid battery cell 212, u H is the highest terminal voltage of the lead-acid battery cell 212, u L is the lowest terminal voltage of the lead-acid battery cell 212, SOC H The SOC is the state of charge corresponding to the highest terminal voltage of the lead-acid battery cell 212. L The state of charge of the lead-acid battery cell 212 corresponds to the lowest terminal voltage; according to the state of charge of the series-connected lead-acid battery cell 212 and the state of charge of the lithium battery cell 211 being the same, the state of charge of the hybrid battery 21 is calibrated.

[0060] In order to allow the capacitor module 3 to supplement the insufficient power output of the hybrid battery module 2 under low temperature conditions, in one embodiment of the present invention, the capacitor module 3 is composed of multiple groups of super capacitor groups 31 connected in parallel, and the super capacitor group 31 is composed of multiple super capacitors 311 connected in series. In order to achieve power output control of the super capacitor 311, the capacitor module 3 and the hybrid battery module 2 are connected through a bidirectional Buck-boost circuit structure 4, and the hybrid battery module 2 can preferentially supply power to the capacitor module 3, so that the super capacitor 311 can preferentially supplement power output under low temperature conditions. In one embodiment of the present invention, the control detector first obtains the SOC of the lithium battery cell 211, and at the same time obtains the maximum discharge current of the lithium battery cell 211 according to formula (3).

[0061] Among them, i max is the maximum discharge current of the lithium battery cell 211, C is the battery capacity of the lead-acid battery cell 212 and the lithium battery cell 211, SOC is the current state of charge of the lithium battery cell 211, SOC L is the state of charge corresponding to the lowest terminal voltage of the lead-acid battery cell 212, and Δt is the discharge time. When the hybrid battery 21 is discharging, the corresponding maximum discharge current is obtained.

[0062] In order to ensure that the hybrid battery module 2 and the capacitor module 3 can achieve performance reliability under low temperature conditions, in one embodiment of the present invention, the control detector first sets the rated discharge power of the battery system, and simultaneously obtains the total voltage of the hybrid battery module 2 and the total voltage of the capacitor module 3, and determines the discharge power composition of the battery system according to formula (4), P = i max U1+i c U2, (4)

[0063] Where P is the discharge power set by the battery system, U1 is the total voltage of the hybrid battery module 2, U2 is the total voltage of the capacitor module 3, i max is the maximum discharge current of the lithium battery cell 211. Under the condition of energy conservation, the power output composition of the hybrid battery module 2 and the capacitor module 3 is determined, thereby determining the performance of the capacitor module 2, fundamentally solving the problem of insufficient performance of the hybrid battery pack under low temperature conditions. When the discharge power of the hybrid battery module 2 meets the rated discharge power of the battery system, at this time i c The discharge current is 0; when the discharge power of the hybrid battery module 2 does not meet the rated discharge power of the battery system, the discharge current of the capacitor module 3 is determined according to formula (5),

[0064] Where P is the discharge power set by the battery system, U1 is the total voltage of the hybrid battery module 2, U2 is the total voltage of the capacitor module 3, i maxis the maximum discharge current of the lithium battery cell 211. By changing the formula, it is determined whether the capacitor module 3 can operate at low temperature or at a limit power, and the discharge current of the capacitor module 3 is calculated to supplement the output power.

[0065] like Figure 2 The figure is a circuit connection diagram of a deep hybrid battery system according to an embodiment of the present invention. In order to meet the charging and discharging requirements of the capacitor module 3 and the hybrid battery module 2 and avoid redundant circuit connection structures, in one embodiment of the present invention, the bidirectional Buck-boost circuit structure 4 includes a first diode 41, a second diode 42, a first switch 43, a second switch 44, and a first inductor 45. The positive electrode of the first diode 41 is connected to one end of the positive electrode line of the bidirectional Buck-boost circuit structure 4; one end of the first switch 43 is connected to the positive electrode of the first diode 41, and the other end of the first switch 43 is connected to the negative electrode of the first diode 41; one end of the second switch 44 is connected to the positive electrode of the first diode 41; The cathode of the first diode 41 is connected, and the other end of the second switch 43 is connected to one end of the cathode line of the bidirectional Buck-boost circuit structure 2; the anode of the second diode 42 is connected to one end of the second switch 44, the cathode of the second diode 42 is connected to the other end of the second switch 44, and the cathode of the second diode 44 is connected to the other end of the cathode line of the bidirectional Buck-boost circuit structure 2; one end of the first inductor 45 is connected to the anode of the second diode 42, and the other end of the first inductor 45 is connected to the other end of the cathode line of the bidirectional Buck-boost circuit structure 2.

[0066] A second aspect of the present invention provides a new energy vehicle, comprising a deep hybrid battery system as described in any one of the above claims.

[0067] Through the above technical solution, the battery system adopts a hybrid battery module connected in series and parallel, which is composed of a lead-acid battery cell and multiple lithium battery cells in series, and the capacity of the lead-acid battery cell and the lithium battery cell are set to be the same, ensuring that the SOC calculation formula can realize the calculation of the SOC of the single battery in the entire hybrid battery group to obtain the SOC in the hybrid battery group. At the same time, the SOC of the lead-acid battery changes linearly with the terminal voltage within a certain range, which can realize the accurate calculation and calibration of the SOC of the hybrid battery module; a series-parallel capacitor module and a bidirectional Buck-boost circuit structure are set, the hybrid battery module preferentially charges the capacitor module, and the hybrid battery module and the capacitor module are deeply mixed to ensure that the battery system still has reliable power output at low temperatures, thereby solving the problem of poor low-temperature performance from the root.

[0068] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0069] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A deep hybrid battery system, characterized in that: The battery system comprises: A DC / DC module, wherein a positive input terminal of the DC / DC module is connected to a positive terminal of an external DC bus, and a negative input terminal of the DC / DC module is connected to a negative terminal of the external DC bus; A hybrid battery module, wherein the positive terminal of the hybrid battery module is connected to the positive output terminal of the DC / DC module, the negative terminal of the hybrid battery module is connected to the negative output terminal of the DC / DC module, and the hybrid battery module is composed of multiple groups of hybrid batteries connected in parallel, and the hybrid battery is composed of a lead-acid battery cell and multiple lithium battery cells connected in series; A bidirectional Buck-boost circuit structure, wherein one end of a positive electrode circuit of the bidirectional Buck-boost circuit structure is connected to a positive terminal of the hybrid battery module, and one end of a negative electrode circuit of the bidirectional Buck-boost circuit structure is connected to a negative terminal of the hybrid battery module; A capacitor module, wherein the positive terminal of the capacitor module is connected to the other end of the positive line of the bidirectional Buck-boost circuit structure, the negative terminal of the capacitor module is connected to the other end of the negative line of the bidirectional Buck-boost circuit structure, and the positive terminal of the capacitor module is connected to the positive output terminal of the DC / DC module, and the negative terminal of the capacitor module is connected to the negative output terminal of the DC / DC module.

2. The battery system according to claim 1, characterized in that: The lead-acid battery cells and the lithium battery cells have the same battery capacity.

3. The battery system according to claim 2, characterized in that: The battery system further comprises a control detector, which is used to: Obtaining the charge and discharge currents of the lead-acid battery cells and the lithium battery cells, and calculating the charge state of the single cells of the hybrid battery according to the charge and discharge currents of the lead-acid battery cells and the lithium battery cells and formula (1), Among them, SOC is the state of charge of the lead-acid battery cell and the lithium battery cell, SOC0 is the initial state of charge of the lead-acid battery cell and the lithium battery cell, i is the charge and discharge current of the lead-acid battery cell and the lithium battery cell, and C is the battery capacity of the lead-acid battery cell and the lithium battery cell.

4. The battery system according to claim 3, characterized in that: The control detector is used to: Obtaining the terminal voltage of the lead-acid battery cell; Calculating the state of charge of the lead-acid battery cell according to the terminal voltage of the lead-acid battery cell and formula (2), and calibrating the state of charge of the hybrid battery, Among them, SOC x is the state of charge of the lead-acid battery cell, u x is the terminal voltage of the lead-acid battery cell, u H is the highest terminal voltage of the lead-acid battery cell, u L is the lowest terminal voltage of the lead-acid battery cell, SOC H SOC is the state of charge corresponding to the highest terminal voltage of the lead-acid battery cell. L The state of charge corresponding to the lowest terminal voltage of the lead-acid battery cell; According to the state of charge of the lead-acid battery cells connected in series being the same as the state of charge of the lithium battery cells, the state of charge of the hybrid battery is calibrated.

5. The battery system according to claim 4, characterized in that: The capacitor module is composed of multiple groups of super capacitors connected in parallel, and the super capacitor group is composed of multiple super capacitors connected in series.

6. The battery system according to claim 5, characterized in that: The control detector is used to: Obtain the SOC of the lithium battery cell, and obtain the maximum discharge current of the lithium battery cell according to formula (3). Among them, i max is the maximum discharge current of the lithium battery cell, C is the battery capacity of the lead-acid battery cell and the lithium battery cell, SOC is the current state of charge of the lithium battery cell, SOC L is the state of charge corresponding to the lowest terminal voltage of the lead-acid battery cell, and Δt is the discharge time.

7. The battery system according to claim 6, characterized in that: The control detector is used to: The rated discharge power of the battery system is set, the total voltage of the hybrid battery module and the total voltage of the capacitor module are obtained, and the discharge power composition of the battery system is determined according to formula (4). P=i max U1+i c U2, (4) Wherein, P is the discharge power set by the battery system, U1 is the total voltage of the hybrid battery module, U2 is the total voltage of the capacitor module, i max is the maximum discharge current of the lithium battery cell; When the discharge power of the hybrid battery module meets the rated discharge power of the battery system, c The discharge current is 0; When the discharge power of the hybrid battery module does not meet the rated discharge power of the battery system, the discharge current of the capacitor module is determined according to formula (5): Wherein, P is the discharge power set by the battery system, U1 is the total voltage of the hybrid battery module, U2 is the total voltage of the capacitor module, i max is the maximum discharge current of the lithium battery cell.

8. The battery system according to claim 1, characterized in that: The bidirectional Buck-boost circuit structure includes: A first diode, wherein an anode of the first diode is connected to one end of a positive electrode line of the bidirectional Buck-boost circuit structure; a first switch, wherein one end of the first switch is connected to the anode of the first diode, and the other end of the first switch is connected to the cathode of the first diode; a second switch, wherein one end of the second switch is connected to the cathode of the first diode, and the other end of the second switch is connected to one end of the cathode line of the bidirectional Buck-boost circuit structure; a second diode, wherein an anode of the second diode is connected to one end of the second switch, a cathode of the second diode is connected to the other end of the second switch, and a cathode of the second diode is connected to the other end of the negative electrode line of the bidirectional Buck-boost circuit structure; A first inductor, one end of the first inductor is connected to the anode of the second diode, and the other end of the first inductor is connected to the other end of the anode line of the bidirectional Buck-boost circuit structure.

9. A new energy vehicle, characterized in that: include: A deep hybrid battery system as claimed in any one of claims 1 to 8.

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